(i) Field of the Invention
The present invention relates to a device for processing circuit supports with plasma excited by a microwave, particularly to a device capable of performing plasma processing for, e.g., surface-refining or etching to both surfaces of a large number of circuit supports such as flexible circuit boards at a time.
(ii) Description of the Related Art
Plasma processing devices of microwave excitation type are used in many fields. FIG. 6 shows an example of such a device, in which a waveguide 51 is disposed at an insulator window hermetically attached to an upper portion of a quartz chamber 50. A magnetron 52 is disposed at the top of the waveguide 51. An object 54 to be processed is placed on an insulator table 53 in the quartz chamber 50. Reaction gas 55 is introduced into the quartz chamber 50 through one portion thereof while the chamber is exhausted with a vacuum pump through a vacuum exhaust port 57. The vacuum pressure in the quartz chamber 50 is checked with a pressure gauge 56, and then the magnetron 52 is energized to perform aimed plasma processing to the object 54. Plasma processing devices of this type are widely used for, e.g., etching or CVD processes for semiconductor wafers.
FIG. 7 shows another example, in which the interior of a metal chamber 60 is hermetically divided with an insulator window 62, and a magnetron 61 is disposed at the top of the chamber above the window. An object 64 to be processed is placed on an insulator table 63 in the metal chamber 60. Reaction gas 65 is introduced into the metal chamber 60 through one portion thereof while the chamber is exhausted with a vacuum pump through a vacuum exhaust port 67. The vacuum pressure in the metal chamber 60 is checked with a pressure gauge 66, and then the magnetron 61 is energized to perform aimed plasma processing to the object 64. Plasma processing devices of this type are widely used for etching processes for semiconductors, TFTs, printed-circuit boards, etc., or in other various fields for, e.g., ashing photoresist, etching, or cleaning or refining surfaces.
Such plasma processing devices as described above, however, can process only one or few objects at a time in consideration of uniformity in processing over the objects. This is because the surface of each object to be processed faces the plasma source and so their locations are restricted by the space in cross section of the chamber and the plasma distribution therein.